1. Field of the Invention
This invention relates to an apparatus and method for continuously producing at a substantially constant flow rate a strip of dough of substantially uniform dimensions, which apparatus and method is used for producing bread or confectionery.
2. Prior Art
Conventionally, automated dough stretching machines and other types of dough processing machines receive a strip of dough fed from the hopper on conveyors. The dimensions of such a dough strip are not regulated before it enters the machines.
U.S. Pat. No. 4,192,636 discloses an apparatus for continuously stretching dough for cakes, bread and the like, comprising a roller mechanism having a plurality of rollers progressing along a closed envelope including a straight portion, and a plurality of conveyor belts arranged in series and disposed under the rollers. The conveying path of the conveyors is spaced apart from the straight portion of the roller mechanism. In this apparatus, dough is supplied directly from the hopper to an upstream conveyor and is conveyed into the space between the roller mechanism and the conveying path of the conveyors. Since the conveyors are driven so that each conveyor moves faster than the nearest upstream conveyor, the dough is stretched by the difference of the speeds of the conveyors, while being held down by the rollers.
However, since the dough readily stops at the exit port of the hopper, it is difficult to supply the dough at a substantially constant flow rate. Further, since the dimensions of the dough are not regulated before it is conveyed into the space between the roller mechanism and the conveyors, the dough is subjected to excessive pressure. This causes a turbulent flow to be generated in it when it enters the space, if part of the dough supplied to the stretching apparatus is too thick. In the case of bread dough, especially, its gluten structure tends to be destroyed due to the pressure. In contrast, if part of the dough supplied is too thin, the straight portion of the roller mechanism cannot hold the dough, and thus the apparatus cannot stretch the dough. Thus, it has been required that a dough strip of uniform dimensions suitable for the apparatus be continuously supplied to it at a substantially constant flow rate.
The same situation arises in other types of dough processing machines, such as flow-rate regulating machines and multiple-layer forming machines if dough from the hopper is directly supplied to these machines on conveyors.